13th International Scientific and Technical Conference

From Imagery to Map: Digital Photogrammetric Technologies

Scientific UAS training for mapping

Smirnov AlexeyManager of Technical Support Department, Racurs

September 2013, Fontainebleau, France

Scientific training area MIIGAiK

Department of photogrammetry

June 2013

UAS Models

GeoScan 101Gatewing X100

Ptero-E5

Objectives

Process Ptero UAS imagery with high-precision projection centers coordinates

Compare accuracy of adjustment for Ptero data over small area vs whole block

Compare accuracy of adjustment results from different UAS models

Technological workflow

Orthophoto control

DEMAerotriangulation

Objects

Area 4 sq.km. Road 5 km.

Testing with accurate centers (Ptero)

GPS position adjustment accuracy (using Obninsk base station) is 6 cm

*

* By GNSS+ company

Spatial offset

Offset vector : x=0.047 m, y=0.110 m, z=0.194 m

Time offset

Nikon D800NovAtel OEM615

Synchronization problem is caused by two-curtain shutter

Adjustment result by centers

Errors

Projection Centers~30 cm by XY

Check points

~33 cm by XY

~20 cm by Z

~34 cm by Z

GCD – 2 cm

Adjustment result by centers and GCPs

Errors

Projection Centers~30 cm by XY

Check points

~16 cm by XY

~16 cm by Z

~16 cm by Z

GCD – 2 cm

Orthophoto quality

GSD – 2 cm

Orthophoto accuracy (relative)

Positional accuracy Δ ~ 18 cm

Vectors from stereo of DiMAC survey

Orthophoto accuracy (absolute)

E abs

Δmin. – 6 cm

Δmax. – 16 cm

Accuracy corresponds to scale 1:2000

Small test area (Ptero)

Errors

Projection Centers~17 cm by XY

Check points

~7 cm by XY

~10 cm by Z

~9 cm by Z

Small test area (Ptero)

E abs

Δmin. – 2 cm

Δmax. – 7 cm

Accuracy corresponds to scale 1:1000

Small test area (GeoScan)

Errors

Projection Centers~3 m by XY

Check points

~22 cm by XY

~16 m by Z

~30 cm by Z

GSD – 7.2 cm

Small test area (GeoScan)

E abs

Δmin. – 13 cm

Δmax. – 23 cm

Accuracy corresponds to scale 1:2000

Small test area (Gatewing)

Errors

Projection Centers~7.5 m by XY

Check points

~6 cm by XY

~20 m by Z

~18 cm by Z

GSD – 4.7 cm

Small test area (Gatewing)

E abs

Δmin. – 14 cm

Δmax. – 22 cm

Accuracy corresponds to scale 1:2000

Difference

Models Camera

altitude, m

Number of

frames

Area,sq.m.

Centers accuracy

Orthophoto accuracy (absolute)

,cm

GSD,cm/pix

Ptero-E5

Nikon D800

(calibrated)

~250

97 280

~17 cm by XY

~10 cm by Z

72.2

GeoScan 101

Sony NEX-5R

~200

38 800

~3 m by XY

~16 m by Z

237.2

Gatewing X100 Ricoh-GR

~150

130 360

~7.5 m by XY

~20 m by Z

22

4.7

Conclusions

Prerequisites for obtaining large scale orthophoto

Use differential GNSS for projection centers

coordinates

Avoid large heading-pitch-roll angles

Use appropriate ground control

Use appropriate GSD

Use calibrated camera

Thank you for attention